Micronutrient-enhanced polymeric seed coatings

ABSTRACT

Improved, micronutrient-supplemented polymeric seed coatings are provided which include at least one polyanionic polymer in combination with respective amounts of Zn, Mn, and Cu micronutrients. Preferably, the coatings comprise polyanionic polymers having a backbone comprising dicarboxylic repeat units with Zn, Mn, and Cu bound to the backbone. The most preferred polymers contain maleic and itaconic repeat units, optionally with sulfonate repeat units. The invention also provides a method of treating seeds using the coatings, and coated seed products.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 14/447,858, filed on Jul. 31, 2014, which claimsthe benefit of U.S. Provisional Patent Application No. 62/001,370, filedon May 21, 2014, and U.S. Provisional Patent Application No. 61/862,301,filed on Aug. 5, 2013, the disclosures of which are incorporated hereinby reference in their entirety for all purposes.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention is concerned with polymers useful for coating ofseeds (e.g., wheat and corn) in order to increase yields. Moreparticularly, the invention is concerned with such polymers, andespecially those containing maleic and itaconic moieties or repeatunits, which are enhanced by the addition of certain micronutrients inspecific amounts, and corresponding methods preparing and using suchpolymers.

Description of the Prior Art

Many factors influence the health and eventual yield of crops, e.g.,moisture, soil quality, plant nutrition including micronutrients,genetics, and ambient temperatures all play roles in determining grainand biomass development. It has been found that insufficientmicronutrients can significantly lessen yields, particularlyinsufficient amounts of Zn, Mn, and Cu.

It has also been known to coat wheat seeds with nutrient-bearing coatingvehicles. See, e.g., Scott et al., Effect of Nutrient Seed Coating onthe Emergence of Wheat and Oats, Fertilizer Research: 205-217 (1987).Some coatings, such as dicalcium phosphate dihydrate, increase early drymatter production and phosphorous (P) uptake. It has also been suggestedthat synthetic resin polymers may be applied to seeds to good effect, asdisclosed in U.S. Pat. No. 6,753,395.

There is accordingly a need in the art for improved coatingsspecifically designed for application to seeds in order to increase cropyields.

SUMMARY OF THE INVENTION

The present invention overcomes the problems outlined above and providesnovel seed coatings having particular amounts of useful micronutrients,and especially Zn, Mn, and Cu. Advantageously, the coatings comprise anaqueous dispersion or solution of anionic carboxylate polymerscontaining maleic and itaconic repeat units together withmicronutrients. The micronutrients may be chemically bound to thepolymers, complexed therewith, or simply present along with thepolymers. Preferably, the micronutrients are directly bonded orcomplexed with the polymer backbone and the micronutrient packageconsists essentially of, or consists of, Zn, Mn, and Cu. Optionally, oneor more plant growth regulators may also be used with the polymers.

The polymers are normally synthesized via free radical polymerization toyield the free acid forms thereof, and are then reacted with compounds(e.g., salts) of Zn, Mn, and Cu in order to yield partial salt forms ofthe polymer in aqueous dispersion with an acidic pH, preferably a pH offrom about 3-8, more preferably from about 4-6.5; in some instances,pure metals may be used in lieu of the metal compounds. These polymersmay be directly applied to seeds by spraying, dipping, or any otherconvenient technique, and allowed to dry thereon, such that the finalseed product has the dried residue of the polymer on the surfacesthereof.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The polymers of the invention provide micronutrients which improve plantgrowth and yields. Preferably, the polymers are polyanionic, andespecially dicarboxylic, and contain maleic and itaconic repeat unitssupplemented with Zn, Mn, and Cu micronutrients.

The Polyanionic Polymers

Generally speaking, the polymers of the invention should have amolecular weight of about 500-5,000,000, more preferably from about1500-50,000, and contain at least three and preferably more repeat unitsper molecule (preferably from about 10-500). Moreover, the partial orcomplete salts of the polymers should be water dispersible andpreferably water soluble, i.e., they should be dispersible or soluble inpure water to a level of at least about 5% w/w at room temperature withmild agitation.

Advantageously, at least about 50% (by mole) of repeat units contain atleast 1 carboxylate group. These species also are typically capable offorming stable solutions in pure water up to at least about 20% w/wsolids at room temperature.

To summarize, the preferred polymers of the invention have the followingcharacteristics:

-   -   The polymers should be dispersible and more preferably fully        soluble in water.    -   The polymers should have a significant number of anionic        functional groups, preferably at least about 90 mole percent by        weight, more preferably at least about 96 mole percent by        weight, and most preferably the polymers are essentially free of        non-anionic functional groups.    -   The polymers are stable thermally and chemically for convenient        use.    -   The polymers should be essentially free of ester groups, i.e.,        no more than about 5 mole percent thereof, and most preferably        no more than about 1 mole percent.    -   The polymers should have only a minimum number of        amide-containing repeat units, preferably no more than about 10        mole percent thereof, and more preferably no more than about 5        mole percent.    -   The polymers should have only a minimum number of        monocarboxylate repeat units, preferably no more than about 10        mole percent thereof, and more preferably no more than about 5        mole percent.

The ensuing detailed description of preferred polymers makes use of theart-accepted term “repeat units” to identify the repeat units in thepolymers. As used herein, “repeat unit” refers to chemically convertedforms (including isomers and enantiomers) of initially chemicallycomplete monomer molecules, where such repeat units are created duringpolymerization reactions, with the repeat units bonding with otherrepeat units to form a polymer chain. Thus, a type B monomer will beconverted to a type B repeat unit, and type C and type G monomers willbe converted type C and G repeat units, respectively. For example, thetype B maleic acid monomer will be chemically converted owing topolymerization conditions to the corresponding type B maleic acid repeatunit, as follows:

Different monomers within a given polymerization mixture are convertedto corresponding repeat units, which bond to each other in various waysdepending upon the nature of the repeat groups and the polymerizationreaction conditions, to create the final polymer chain, apart from endgroups.

In carrying out the invention, it has been determined that certainspecific families or classes of polymers are particularly suitable.These are described below as “Class I,” “Class IA,” and “Class II”polymers. Of course, mixtures of these polymer classes are alsocontemplated.

Class I Polymers

The Class I polyanionic polymers of the present invention are at leasttetrapolymers, i.e., they are composed of at least four different repeatunits individually and independently selected from the group consistingof type B, type C, and type G repeat units, and mixtures thereof,described in detail below. However, the Class I polymers comprehendpolymers having more than four distinct repeat units, with the excessrepeat units being selected from the group consisting of type B, type C,and type G repeat units, and mixtures thereof, as well as other monomersor repeat units not being type B, C, or G repeat units.

Preferred Class I polymers contain at least one repeat unit from each ofthe B, C, and G types, one other repeat unit selected from the groupconsisting of type B, type C, and type G repeat units, and optionallyother repeat units not selected from type B, type C, and type G repeatunits. Particularly preferred polymers comprise a single type B repeatunit, a single type C repeat unit, and two different type G repeatunits, or two different type B repeat units, a single type C repeatunit, and one or more different type G repeat units.

However constituted, preferred Class I polymers contain at least about90 mole percent (more preferably at least about 96 mole percent) ofrepeat units selected from the group consisting of type B, C, and Grepeat units (i.e., the polymers should contain no more than about 10mole percent (preferably no more than about 4 mole percent) of repeatunits not selected from types B, C, and G).

The Class I polymers are easily converted to partial or fully saturatedsalts by a simple reaction with an appropriate salt-forming cationcompound. Usable cations can be simple cations such as sodium, but morecomplex cations can also be used, such as cations containing a metalatom and other atom(s) as well, e.g., vanadyl cations. Among preferredmetal cations are those derived from alkali, alkaline earth, andtransition metals. The cations may also be amines (as used herein,“amines” refers to primary, secondary, or tertiary amines, monoamines,diamines, and triamines, as well as ammonia, ammonium ions, quaternaryamines, quaternary ammonium ions, alkanolamines (e.g., ethanolamine,diethanolamine, and triethanolamine), and tetraalkylammonium species).The most preferred class of amines are alkyl amines, where the alkylgroup(s) have from 1-30 carbon atoms and are of straight or branchedchain configuration. Such amines should be essentially free of aromaticrings (no more than about 5 mole percent aromatic rings, and morepreferably no more than about 1 mole percent thereof). A particularlysuitable alkyl amine is isopropylamine. These possible secondary cationsshould be reacted with no more than about 10 mole percent of the repeatunits of the polymer.

1. Type B Repeat Units

Type B repeat units are dicarboxylate repeat units derived from monomersof maleic acid and/or anhydride, fumaric acid and/or anhydride,mesaconic acid and/or anhydride, substituted maleic acid and/oranhydride, substituted fumaric acid and/or anhydride, substitutedmesaconic acid and/or anhydride, mixtures of the foregoing, and anyisomers, esters, acid chlorides, and partial or complete salts of any ofthe foregoing. As used herein with respect to the type B repeat units,“substituted” species refers to alkyl substituents (preferably C1-C6straight or branched chain alkyl groups substantially free of ringstructures), and halo substituents (i.e., no more than about 5 molepercent of either ring structures or halo substituents, preferably nomore than about 1 mole percent of either); the substituents are normallybound to one of the carbons of a carbon-carbon double bond of themonomer(s) employed. In preferred forms, the total amount of type Brepeat units in the Class I polymers of the invention should range fromabout 1-70 mole percent, more preferably from about 20-65 mole percent,and most preferably from about 35-55 mole percent, where the totalamount of all of the repeat units in the Class I polymer is taken as 100mole percent.

Maleic acid, methylmaleic acid, maleic anhydride, methylmaleicanhydride, and mesaconic acid (either alone or as various mixtures) arethe most preferred monomers for generation of type B repeat units. Thoseskilled in the art will appreciate the usefulness of in situ conversionof acid anhydrides to acids in a reaction vessel just before or evenduring a reaction. However, it is also understood that whencorresponding esters (e.g., maleic or citraconic esters) are used asmonomers during the initial polymerization, this should be followed byhydrolysis (acid or base) of pendant ester groups to generate a finalcarboxylated polymer substantially free of ester groups.

2. Type C Repeat Units

Type C repeat units are derived from monomers of itaconic acid and/oranhydride, substituted itaconic acid and/or anhydride, as well asisomers, esters, acid chlorides, and partial or complete salts of any ofthe foregoing. The type C repeat units are present in the preferredClass I polymers of the invention at a level of from about 1-80 molepercent, more preferably from about 15-75 mole percent, and mostpreferably from about 20-55 mole percent, where the total amount of allof the repeat units in the polymer is taken as 100 mole percent.

The itaconic acid monomer used to form type C repeat unit has onecarboxyl group, which is not directly attached to the unsaturatedcarbon-carbon double bond used in the polymerization of the monomer.Hence, the preferred type C repeat unit has one carboxyl group directlybound to the polymer backbone, and another carboxyl group spaced by acarbon atom from the polymer backbone. The definitions and discussionrelating to “substituted,” “salt,” and useful salt-forming cations(metals, amines, and mixtures thereof) with respect to the type C repeatunits, are the same as those set forth for the type B repeat units.

Unsubstituted itaconic acid and itaconic anhydride, either alone or invarious mixtures, are the most preferred monomers for generation of typeC repeat units. Again, if itaconic anhydride is used as a startingmonomer, it is normally useful to convert the itaconic anhydride monomerto the acid form in a reaction vessel just before or even during thepolymerization reaction. Any remaining ester groups in the polymer arenormally hydrolyzed, so that the final carboxylated polymer issubstantially free of ester groups.

3. Type G Repeat Units

Type G repeat units are derived from substituted or unsubstitutedsulfonate-bearing monomers possessing at least one carbon-carbon doublebond and at least one sulfonate group, in acid, partial or completesalt, or other form, and which are substantially free of aromatic ringsand amide groups (i.e., no more than about 5 mole percent of eitheraromatic rings or amide groups, preferably no more than about 1 molepercent of either). The type G repeat units are preferably selected fromthe group consisting of C1-C8 straight or branched chain alkenylsulfonates, substituted forms thereof, and any isomers or salts of anyof the foregoing; especially preferred are alkenyl sulfonates selectedfrom the group consisting of vinyl, allyl, and methallylsulfonic acidsor salts. The total amount of type G repeat units in the Class Ipolymers of the invention should range from about 0.1-65 mole percent,more preferably from about 1-35 mole percent, and most preferably fromabout 1-25 mole percent, where the total amount of all of the repeatunits in the Class I polymer is taken as 100 mole percent. Thedefinitions and discussion relating to “substituted,” “salt,” and usefulsalt-forming cations (metals, amines, and mixtures thereof) with respectto the type G repeat units, are the same as those set forth for the typeB repeat units.

Vinylsulfonic acid, allylsulfonic acid, and methallylsulfonic acid,either alone or in various mixtures, are deemed to be the most preferredmonomers for generation of type G repeat units. It has also been foundthat alkali metal salts of these acids are also highly useful asmonomers. In this connection, it was unexpectedly discovered that duringpolymerization reactions yielding the novel polymers of the invention,the presence of mixtures of alkali metal salts of these monomers withacid forms thereof does not inhibit completion of the polymerizationreaction.

Further Preferred Characteristics of the Class I Polymers

As noted previously, the total abundance of type B, C, and G repeatunits in the Class I polymers of the invention is preferably at leastabout 90 mole percent, more preferably at least about 96 mole percent,and most preferably the polymers consist essentially of or are 100 molepercent B, C, and G-type repeat units. It will be understood that therelative amounts and identities of polymer repeat units can be varied,depending upon the specific properties desired in the resultantpolymers. Moreover, it is preferred that the Class I polymers of theinvention contain no more than about 10 mole percent of any of (I)non-carboxylate olefin repeat units, (ii) ether repeat units, (iii)ester repeat units, (iv) non-sulfonated monocarboxylic repeat units, and(v) amide-containing repeat units. “Non-carboxylate” and“non-sulfonated” refers to repeat units having essentially nocarboxylate groups or sulfonate groups in the corresponding repeatunits, namely less that about 55 by weight in the repeat units.Advantageously, the mole ratio of the type B and type C repeat units incombination to the type G repeat units (that is, the mole ratio of(B+C)/G) should be from about 0.5-20:1, more preferably from about2:1-20:1, and still more preferably from about 2.5:1-10:1. Stillfurther, the polymers should be essentially free (e.g., less than about1 mole percent) of alkyloxylates or alkylene oxide (e.g., ethyleneoxide)-containing repeat units, and most desirably entirely freethereof.

The preferred Class I polymers of the invention have the repeat unitsthereof randomly located along the polymer chain without any orderedsequence of repeat units. Thus, the polymers hereof are not, e.g.,alternating with different repeat units in a defined sequence along thepolymer chain.

It has also been determined that the preferred Class I polymers of theinvention should have a very high percentage of the repeat units thereofbearing at least one anionic group, e.g., at least about 80 molepercent, more preferably at least about 90 mole percent, and mostpreferably at least about 95 mole percent. It will be appreciated thatthe B and C repeat units have two anionic groups per repeat unit,whereas the preferred sulfonate repeat units have one anionic group perrepeat unit.

For a variety of applications in accordance with the invention, certaintetrapolymer compositions are preferred, i.e., a preferred polymerbackbone composition range (by mole percent, using the parent monomernames of the corresponding repeat units) is: maleic acid 35-50%;itaconic acid 20-55%; methallylsulfonic acid 1-25%; and allylsulfonicsulfonic acid 1-20%, where the total amount of all of the repeat unitsin the polymer is taken as 100 mole percent. It has also been found thateven small amounts of repeat units, which are neither B nor C repeatunits, can significantly impact the properties of the final polymers, ascompared with prior BC polymers. Thus, even 1 mole percent of each of 2different G repeat units can result in a tetrapolymer exhibitingdrastically different behaviors, as compared with BC polymers.

The molecular weight of the polymers is also highly variable, againdepending principally upon the desired properties. Generally, themolecular weight distribution for polymers in accordance with theinvention is conveniently measured by size exclusion chromatography.Broadly, the molecular weight of the polymers ranges from about800-50,000, and more preferably from about 1000-5000. For someapplications, it is advantageous that at least 90% of the finishedpolymer be at or above a molecular weight of about 1000 measured by sizeexclusion chromatography in 0.1 M sodium nitrate solution via refractiveindex detection at 35° C. using polyethylene glycol standards. Ofcourse, other techniques for such measurement can also be employed.

Especially preferred Class I polymers for use in the invention aresynthesized as partial Zn, Mn, and Cu combined salts and include thefollowing repeat units: maleic—from about 20-55 mole percent, morepreferably from about 25-50 mole percent, and most preferably from about30-45 mole percent; itaconic—from about 35-65 mole percent, morepreferably from about 40-60 mole percent, and most preferably about 50mole percent; total sulfonated—from about 2-40 mole percent, morepreferably from about 3-25 mole percent, and most preferably from about5-20 mole percent. The total sulfonated fraction is preferably made upof a combination of methallylsulfonic and allylsulfonic repeat units,namely, methallylsulfonic—from about 1-20 mole percent, more preferablyfrom about 3-15 mole percent, and most preferably from about 4-6 molepercent, and allylsulfonic—from about 0.1-10 mole percent, morepreferably from about 0.5-8 mole percent, and most preferably from about1-5 mole percent. These partial salts should have a pH within the rangeof from about 3-8, more preferably from about 4-6.5.

One preferred polymer of this type has a repeat unit molar compositionof maleic 45 mole percent, itaconic 50 mole percent, methallylsulfonic 4mole percent, and allylsulfonic 1 mole percent. This specific polymer isreferred to herein as the “T5” polymer, and would be synthesized as orconverted to the desired Zn, Mn, and Cu combined partial salt.

Another type of preferred polymer is a “T-20” tetrapolymer containingabout 30 mole percent maleic repeat units, about 50 mole percentitaconic repeat units, and a total of about 20 mole percent sulfonatedrepeat units, made up of about 15 mole percent methallylsulfonate repeatunits and about 5 mole percent allylsulfonate repeat units. The T-20polymer would be synthesized as or converted to the desired Zn, Mn, andCu combined partial salt.

Syntheses of the Class I Polymers

Virtually any conventional method of free radical polymerization may besuitable for the synthesis of the Class I polymers of the invention.However, a preferred and novel synthesis may be used, which isapplicable not only for the production of the Class I polymers of theinvention, but also for the synthesis of polymers containingdicarboxylate repeat units and sulfonate repeat units and preferablycontaining at least one carbon-carbon double bond.

Generally speaking, the new synthesis methods comprise carrying out afree radical polymerization reaction between dicarboxylate and sulfonaterepeat units in the presence of hydrogen peroxide andvanadium-containing species to achieve a conversion to polymer in excessof 90%, and more preferably in excess of 98%, by mole. That is, adispersion of the dicarboxylate and sulfonated monomers is created andfree radical initiator(s) are added followed by allowing the monomers topolymerize.

Preferably, the hydrogen peroxide is the sole initiator used in thereaction, but in any case, it is advantageous to conduct the reaction inthe absence of any substantial quantities of other initiators (i.e., thetotal weight of the initiator molecules used should be about 95% byweight hydrogen peroxide, more preferably about 98% by weight, and mostpreferably 100% by weight thereof). Various sources of vanadium may beemployed, with vanadium oxysulfates being preferred.

It has been discovered that it is most advantageous to perform thesepolymerization reactions in substantially aqueous dispersions (e.g., atleast about 95% by weight water, more preferably at least about 98% byweight water, and most preferably 100% by weight water). The aqueousdispersions may also contain additional monomer, but only to the minorextent noted.

It has also been found that the preferred polymerization reactions maybe carried out without the use of inert atmospheres, e.g., in an ambientair environment. As is well known in the art, free radicalpolymerization reactions in dispersions are normally conducted in a waythat excludes the significant presence of oxygen. As a result, theseprior techniques involve such necessary and laborious steps asdegassing, inert gas blanketing of reactor contents, monomer treatmentsto prevent air from being present, and the like. These prior expedientsadd to the cost and complexity of the polymerizations, and can presentsafety hazards. However, in the polymerizations of the polymers of thepresent invention, no inert gas or other related steps are required,although they may be employed if desired.

One preferred embodiment comprises creating highly concentrated aqueousdispersions of solid monomer particles (including saturated dispersionscontaining undissolved monomers) at a temperature of from about 50-125°C., more preferably from about 75-110° C., and adding vanadiumoxysulfate to give a vanadium concentration in the dispersion of fromabout 1-1000 ppm, and more preferably from about 5-500 ppm (metalsbasis). This is followed by the addition of hydrogen peroxide over aperiod of from about 30 minutes-24 hours (more preferably from about 1-5hours) in an amount effective to achieve polymerization. This process iscommonly carried out in a stirred tank reactor equipped with facilitiesfor controlling temperature and composition, but any suitable equipmentused for polymerization may be employed.

Another highly preferred and efficient embodiment involves charging astirred tank reactor with water, followed by heating and the addition ofmonomers to give a dispersion having from about 40-75% w/w solidsconcentration. Where maleic and/or itaconic monomers are employed, theymay be derived either from the corresponding acid monomers, or from insitu conversion of the anhydrides to acid in the water. Carboxylate andsulfonated monomers are preferred in their acid and/or anhydride foil″,although salts may be used as well. Surprisingly, it has been found thatincomplete monomer dissolution is not severely detrimental to thepolymerization; indeed, the initially undissolved fraction of monomerswill dissolve at some time after polymerization has been initiated.

After the initial heating and introduction of monomers, the reactorcontents are maintained at a temperature between about 80-125° C., withthe subsequent addition of vanadium oxysulfatc. Up to this point in thereaction protocol, the order of addition of materials is not critical.After introduction of vanadium oxysulfate, a hydrogen peroxide solutionis added over time until substantially all of the monomers are convertedto polymer. Peroxide addition may be done at a constant rate, a variablerate, and with or without pauses, at a fixed or variable temperature.The concentration of peroxide solution used is not highly critical,although the concentration on the low end should not dilute the reactorcontents to the point where the reaction becomes excessively slow orimpractically diluted. On the high end, the concentration should notcause difficulties in performing the polymerization safely in theequipment being used.

Preferably, the polymerization reactions of the invention are carriedout to exclude substantial amounts of dissolved iron species (i.e., morethan about 5% by weight of such species, and more preferablysubstantially less, on the order of below about 5 ppm, and mostadvantageously under about 1 ppm). This is distinct from certain priortechniques requiring the presence of iron-containing materials.Nonetheless, it is acceptable to carry out the polymerization of theinvention in 304 or 316 stainless steel reactors. It is also preferredto exclude from the polymerization reaction any significant amounts (normore than about 5% by weight) of the sulfate salts of ammonium, amine,alkali and alkaline earth metals, as well as their precursors andrelated sulfur-containing salts, such as bisulfites, sulfites, andmetabisulfites. It has been found that use of these sulfate-relatedcompounds leaves a relatively high amount of sulfates and the like inthe final polymers, which either must be separated or left as a productcontaminant.

The high polymerization efficiencies of the preferred syntheses resultfrom the use of water as a solvent and without the need for othersolvents, elimination of other initiators (e.g., azo, hydroperoxide,persulfate, organic peroxides) iron and sulfate ingredients, the lack ofrecycling loops, so that substantially all of the monomers are convertedto the finished polymers in a single reactor. This is further augmentedby the fact that the polymers are formed first, and subsequently, ifdesired, partial or complete salts can be created.

EXAMPLES

The following examples describe preferred synthesis techniques forpreparing polymers; it should be understood, however, that theseexamples are provided by way of illustration only and nothing thereinshould be taken as a limitation on the overall scope of the invention.It will further be understood that the following Examples relate tosynthesis of the stating polymers, which are then converted to partialZn, Mn, and Cu combined salts for use as seed coatings.

Example 1—Exemplary Synthesis

Apparatus:

A cylindrical reactor was used, capable of being heated and cooled, andequipped with efficient mechanical stirrer, condenser, gas outlet (opento atmosphere), solids charging port, liquids charging port, thermometerand peroxide feeding tube.

Procedure: Water was charged into the reactor, stirring was initiatedalong with heating to a target temperature of 95° C. During this phase,itaconic acid, sodium methallylsulfonate, sodium allylsulfonate, andmaleic anhydride were added so as to make a 50% w/w solids dispersionwith the following monomer mole fractions:

-   -   maleic: 45%    -   itaconic: 35%    -   methallylsulfonate: 15%    -   allylsulfonate: 5%        When the reactor temperature reached 95° C., vanadium oxysulfate        was added to give a vanadium metal concentration of 25 ppm by        weight. After the vanadium salt fully dissolved, hydrogen        peroxide (as 50% w/w dispersion) was added continuously over 3        hours, using the feeding tube. The total amount of hydrogen        peroxide added was 5% of the dispersion weight in the reactor        prior to peroxide addition. After the peroxide addition was        complete, the reactor was held at 95° C. for two hours, followed        by cooling to room temperature.

The resulting polymer dispersion was found to have less than 2% w/wtotal of residual monomers as determined by chromatographic analysis.

Example 2—Exemplary Synthesis

Apparatus:

Same as Example 1

Procedure: Water was charged into the reactor, stirring was initiatedalong with heating to a target temperature of 100° C. During this phase,itaconic acid, sodium methallylsulfonate, sodium allylsulfonate, andmaleic anhydride were added so as to make a 70% w/w solids dispersionwith the following monomer mole fractions:

-   -   maleic: 45%    -   itaconic: 50%    -   methallylsulfonate: 4%    -   allylsulfonate: 1%        When the reactor temperature reached 100° C., vanadium        oxysulfate was added to give a vanadium metal concentration of        25 ppm by weight. After the vanadium salt fully dissolved,        hydrogen peroxide (as 50% w/w dispersion) was added continuously        over 3 hours, using the feeding tube. The total amount of        hydrogen peroxide added was 7.5% of the dispersion weight in the        reactor prior to peroxide addition. After the peroxide addition        was complete, the reactor was held at 100° C. for two hours,        followed by cooling to room temperature.

The resulting polymer dispersion was found to have less than 1% w/wtotal of residual monomers as determined by chromatographic analysis.

Example 3—Preparation of Tetrapolymer Partial Salts

A tetrapolymer calcium sodium salt dispersion containing 40% by weightpolymer solids in water was prepared by the preferred free radicalpolymerization synthesis of the invention, using an aqueous monomerreaction mixture having 45 mole percent maleic anhydride, 35 molepercent itaconic acid, 15 mole percent methallylsulfonate sodium salt,and 5 mole percent allylsulfonate. The final tetrapolymer dispersion hada pH of slightly below 1.0 and was a partial sodium salt owing to thesodium cation on the sulfonate monomers. At least about 90% of themonomers were polymerized in the reaction.

The resultant polymer is then conventionally reacted with appropriateZn, Mn, and Cu sources in order to create a final partial salt polymerhaving the desired pH and metal contents for use as seed coatings.

Example 4—Exemplary Synthesis

A terpolymer salt dispersion containing 70% by weight polymer solids inwater was prepared using a cylindrical reactor capable of being heatedand cooled, and equipped with an efficient mechanical stirrer, acondenser, a gas outlet open to the atmosphere, respective ports forcharging liquids and solids to the reactor, a thermometer, and aperoxide feeding tube.

Water (300 g) was charged into the reactor with stirring and heating toa target temperature of 95° C. During heating, itaconic acid, sodiummethallylsulfonate, and maleic anhydride were added so as to make a 75%w/w solids dispersion with the following monomer mole fractions: malcicanhydride—20%; itaconic acid—60%; methallylsulfonate sodium salt—20%.When the monomers were initially added, they were in suspension in thewater. As the temperature rose, the monomers became more fully dissolvedbefore polymerization was initiated, and the maleic anhydride washydrolyzed to maleic acid. When the reactor temperature reached 95° C.,vanadium oxysulfatc was added to yield a vanadium metal concentration of50 ppm by weight of the reactor contents at the time of addition of thevanadium salt. After the vanadium salt fully dissolved, hydrogenperoxide was added as a 50% w/w dispersion in water continuously overtwo hours. At the time of hydrogen peroxide addition, not all of themonomers were completely dissolved, achieving what is sometimes referredto as “slush polymerization”; the initially undissolved monomers weresubsequently dissolved during the course of the reaction. The totalamount of hydrogen peroxide added equaled 5% of the dispersion weight inthe reactor before addition of the peroxide.

After the peroxide addition was completed, the reaction mixture was heldat 95° C. for two hours, and then allowed to cool to room temperature.The resulting polymer dispersion had a pH of slightly below 1.0 and wasa partial sodium salt owing to the sodium cation on the sulfonatemonomers. The dispersion was found to have a monomer content of lessthan 2% w/w, calculated as a fraction of the total solids in thereaction mixture, as determined by chromatographic analysis.Accordingly, over 98% w/w of the initially added monomers were convertedto polymer.

This polymer is then conventionally reacted with Zn, Mn, and Cu salts inorder to yield the partial salt polymers of the invention, at theappropriate pH levels.

Class IA Polymers

Class IA polymers contain both carboxylate and sulfonate functionalgroups, but are not the tetra- and higher order polymers of Class I. Forexample, terpolymers of maleic, itaconic, and allylsulfonic repeatunits, which are per se known in the prior art, will function as thepolyanionic polymer component of the compositions of the invention. TheClass IA polymers thus are normally homopolymers, copolymers, andterpolymers, advantageously including repeat units individually andindependently selected from the group consisting of type B, type C, andtype G repeat units, without the need for any additional repeat units.Such polymers can be synthesized in any known fashion, and can also beproduced using the previously described Class I polymer synthesis.

Class IA polymers preferably have the same molecular weight ranges andthe other specific parameters (e.g., pH and polymer solids loading)previously described in connection with the Class I polymers, and areconverted to the desired partial Zn, Mn, and Cu combined salts, asdescribed previously.

Class II Polymers

Broadly speaking, the polyanionic polymers of this class are of the typedisclosed in U.S. Pat. No. 8,043,995, which is incorporated by referenceherein in its entirety. The polymers include repeat units derived fromat least two different monomers individually and respectively taken fromthe group consisting of what have been denominated for ease of referenceas B′ and C′ monomers; alternately, the polymers may be formed ashomopolymers or polymers from recurring C′ monomers. The repeat unitsmay be randomly distributed throughout the polymer chains.

In detail, repeat unit B′ is of the general formula

orand repeat unit C′ is of the general formula

wherein each R₇ is individually and respectively selected from the groupconsisting of H, OH, C₁-C₃₀ straight, branched chain and cyclic alkyl oraryl groups, C₁-C₃₀ straight, branched chain and cyclic alkyl or arylformate (C₀), acetate (C₁), propionate (C₂), butyrate (C₃), etc. up toC₃₀ based ester groups, R′CO₂ groups, OR′ groups and COOX groups,wherein R′ is selected from the group consisting of C₁-C₃₀ straight,branched chain and cyclic alkyl or aryl groups and X is selected fromthe group consisting of H, the alkali metals, NH₄ and the C₁-C₄ alkylammonium groups, R₃ and R₄ are individually and respectively selectedfrom the group consisting of H, C₁-C₃₀ straight, branched chain andcyclic alkyl or aryl groups, R₅, R₆, R₁₀ and R₁₁ are individually andrespectively selected from the group consisting of H, the alkali metals,NH₄ and the C₁-C₄ alkyl ammonium groups, Y is selected from the groupconsisting of Fe, Mn, Mg, Zn, Cu, Ni, Co, Mo, V, W, the alkali metals,the alkaline earth metals, polyatomic cations containing any of theforegoing (e.g., VO⁺²), amines, and mixtures thereof; and R₈ and R₉ areindividually and respectively selected from the group consisting ofnothing (i.e., the groups are non-existent), CH₂, C₂H₄, and C₃H₆.

As can be appreciated, the Class II polymers typically have differenttypes and sequences of repeat units. For example, a Class II polymercomprising B′ and C′ repeat units may include all three forms of B′repeat units and all three forms of C′ repeat units. However, forreasons of cost and case of synthesis, the most useful Class II polymersare made up of B′ and C′ repeat units. In the case of the Class IIpolymers made up principally of B′ and C′ repeat units, R₅, R₆, R₁₀, andR₁₁ are individually and respectively selected from the group consistingof H, the alkali metals, NH₄, and the C₁-C₄ alkyl ammonium groups. Thisparticular Class II polymer is sometimes referred to as a butanedioicmethylenesuccinic acid polymer and can include various salts andderivatives thereof.

The Class II polymers may have a wide range of repeat unitconcentrations in the polymer. For example, Class II polymers havingvarying ratios of B′:C′ (e.g., 10:90, 60:40, 50:50 and even 0:100) arecontemplated and embraced by the present invention. Such polymers wouldbe produced by varying monomer amounts in the reaction mixture fromwhich the final product is eventually produced and the B′ and C′ typerepeat units may be arranged in the polymer backbone in random order orin an alternating pattern.

The Class II polymers may have a wide variety of molecular weights,ranging for example from 500-5,000,000, depending chiefly upon thedesired end use. Additionally, n can range from about 1-10,000 and morepreferably from about 1-5,000.

Preferred Class II polymers are usually synthesized using dicarboxylicacid monomers, as well as precursors and derivatives thereof. Forexample, polymers containing mono and dicarboxylic acid repeat unitswith vinyl ester repeat units and vinyl alcohol repeat units arecontemplated; however, polymers principally comprised of dicarboxylicacid repeat units are preferred (e.g., at least about 85%, and morepreferably at least about 93%, of the repeat units are of thischaracter). Class II polymers may be readily complexed with salt-formingcations using conventional methods and reactants.

Synthesis of the Class II Polymers of the Invention

In general, the Class II polymers are made by free radicalpolymerization serving to convert selected monomers into the desiredpolymers with repeat units. Such polymers may be further modified toimpart particular structures and/or properties. A variety of techniquescan be used for generating free radicals, such as addition of peroxides,hydroperoxides, azo initiators, persulfates, percarbonatcs, per-acid,charge transfer complexes, irradiation (e.g., UV, electron beam, X-ray,gamma-radiation and other ionizing radiation types), and combinations ofthese techniques. Of course, an extensive variety of methods andtechniques are well known in the art of polymer chemistry for initiatingfree-radical polymerizations. Those enumerated herein are but some ofthe more frequently used methods and techniques. Any suitable techniquefor performing free-radical polymerization is likely to be useful forthe purposes of practicing the present invention.

The polymerization reactions are carried out in a compatible solventsystem, namely a system which does not unduly interfere with the desiredpolymerization, using essentially any desired monomer concentrations. Anumber of suitable aqueous or non-aqueous solvent systems can beemployed, such as ketones, alcohols, esters, ethers, aromatic solvents,water and mixtures thereof. Water alone and the lower (C₁-C₄) ketonesand alcohols are especially preferred, and these may be mixed with waterif desired. In some instances, the polymerization reactions are carriedout with the substantial exclusion of oxygen, and most usually under aninert gas such as nitrogen or argon. There is no particular criticalityin the type of equipment used in the synthesis of the polymers, i.e.,stirred tank reactors, continuous stirred tank reactors, plug flowreactors, tube reactors and any combination of the foregoing arranged inseries may be employed. A wide range of suitable reaction arrangementsare well known to the art of polymerization.

In general, the initial polymerization step is carried out at atemperature of from about 0° C. to about 120° C. (more preferably fromabout 30° C. to about 95° C. for a period of from about 0.25 hours toabout 24 hours and even more preferably from about 0.25 hours to about 5hours). Usually, the reaction is carried out with continuous stirring.

After the polymerization reaction is complete, the Class II polymers areconverted to the Zn, Mn, and Cu combined partial salts at theappropriate pH levels.

Preferred Class II Maleic-Itaconic Polymers

The most preferred Class II polymers are composed of maleic and itaconicB′ and C′ repeat units and have the generalized formula

where X is either H or another salt-forming cation, depending upon thelevel of salt formation.

In a specific example of the synthesis of a maleic-itaconic Class IIpolymer, acetone (803 g), maleic anhydride (140 g), itaconic acid (185g) and benzoyl peroxide (11 g) were stirred together under inert gas ina reactor. The reactor provided included a suitably sized cylindricaljacketed glass reactor with mechanical agitator, a contents temperaturemeasurement device in contact with the contents of the reactor, an inertgas inlet, and a removable reflux condenser. This mixture was heated bycirculating heated oil in the reactor jacket and stirred vigorously atan internal temperature of about 65-70° C. This reaction was carried outover a period of about 5 hours. At this point, the contents of thereaction vessel were poured into 300 g water with vigorous mixing. Thisgave a clear solution. The solution was subjected to distillation atreduced pressure to drive off excess solvent and water. After sufficientsolvent and water have been removed, the solid product of the reactionprecipitates from the concentrated solution, and is recovered. Thesolids are subsequently dried in vacuo. A schematic representation ofthis reaction is shown below.

Once again, the Class II polymers should have the same preferredcharacteristics as those of the Class I and Class IA polymers set forthabove, after conversion to the Zn, Mn, and Cu combined partial salts.Preferred Micronutrient Compositions

As noted previously, the preferred polymers of the invention includerespective amounts of Zn, Mn, and Cu micronutrients. Thus, one type ofmicronutrient-supplemented polymer in accordance with the inventionincludes from about 0.1-12% by weight of Zn, more preferably from about1-9% by weight Zn, and most preferably from about 2-6% by weight Zn.Additionally, these polymers should include from about 0.1-7.5% Mn, morepreferably from about 0.8-4.5% by weight Mn, and most preferably fromabout 1-3% by weight Mn. Cu is preferably present at a level of fromabout 10-1500 ppm, more preferably from about 100-1400 ppm, and mostpreferably from about 600-1200 ppm. All of the foregoing ranges arebased upon the weight percentages of Zn, Mn, and Cu as the correspondingmicronutrient metals per se, and not in terms of compounds containingthe micronutrients. Na is also preferably present in the polymers,derived from sodium hydroxide, at variable levels depending upon the pHof the product. The Zn, Mn, and Cu micronutrients are chemically bounddirectly to the backbone of the polymer.

Polymer formulations having different concentrations of micronutrientsmay be used in practicing the invention. For example, an aqueouspolymeric composition may be provided which is designed for applicationat a rate of 6 oz of the liquid per 100 lbs of seed, in which case theconcentration of the micronutrients would be on the low side of thelisted ranges. Alternately, a more concentrated polymeric compositionmay be formulated for application at a rate of 2 oz of the liquid per100 lbs of seed. In this instance, the micronutrient concentrationswould be towards the high end of the ranges. The latter moreconcentrated compositions would also be designed for mixing with otherplant protection products.

In preparative procedures, the acid form of the polymers areconventionally synthesized as aqueous dispersions or solutions, and theZn, Mn, and Cu micronutrients are reacted with the synthesized polymerso as to cause the micronutrients to chemically bond with or complex tothe polymer to create the desire partial salts. Normally, compounds ofZn, Mn, and Cu are used, e.g., the oxide, carbonate, or sulfatecompounds. Sodium hydroxide is also added to achieve the desired pH.

As noted previously, the compositions of the invention areadvantageously in the form of aqueous polymeric dispersions of acid pHand with a polymer content of from about 30-60% by weight, morepreferably from about 35-55% by weight. In particularly preferred forms,the compositions have a pH of from about 5.8-6.2. Zn is present at alevel of about 2% by weight, Mn is present at a level of about 1% byweight, and Cu is present at a level of about 200 ppm; all of theseamounts are on a w/w, metals basis. Zn is derived form zinc carbonate,whereas the Mn is derived from manganese sulfate, and the Cu is derivedfrom copper oxide. The Na is derived from sodium sulfate. Thecomposition also includes a minor about of propylene glycol at 5% w/wand from about 45-55% w/w of water.

The polymers of the invention are useful with virtually all kinds ofagricultural seeds and particularly wheat, corn, soybean, cotton, andrice. For example, the polymers can be used with essentially all wheatvarieties and hybrids, including, without limitation, the following andall subvarieties thereof:

2137 Aspen Cougar Hickok 2145 Avalanche Culver Hondo 2154 Baker's WhiteCuster Ike 2157 Betty Cutter Infinity CL 2158 Big Dawg Danby Intrada2163 Big Max Deliver Jagalene 2165 Bill Discovery Jagger 2172 Bond CLDoans Jules 2174 Bounty 122 Dodge Kalvesta 2180 Bounty 202 DominatorKarl/Karl 92 Abilene Bounty 205 Dumas Keota Above Bounty 301 DusterKleopatra Red Advantage Bronco Eagle Kleopatra White Agseco 7805 BruleEndurance Kojak Agseco 7833 Buckskin Enhancer Lakin Agseco 7837 OKBullet Fannin Lamar Agseco7846 Burchett Fuller Lancota Agseco 7853Carson G1878 Laredo Agseco 9001 Centerfield Garst HR48 Larned AllianceCentura Garst HR64 Lockett Akron Centurk/Centurk 78 Gem Longhorn AnkorCentury Grazit Mankato AP502CL Champ Guymon Mesa AP7301 Chisholm HallamMillennium AP7501 Cimarron Halt Mustang AP7510 Cisco Harry Nekota AP7601Cody Hatcher Neosho Arapahoe Colby 94 Haven Newton Arkan Colt HawkNiobrara Arlin Coronado Hawken Norkan Art Cossack Heyne NuDakotaNuFrontier Quantum 574 Sturdy 2K TAM 302 NuGrain Quantum 577 T67 TAM 304NuHills Quantum 578 T81 TAM 400 NuHorizon Quantum 579 T81SV TarkioNuplains Quantum 588a T812 Thunderbird Ogallala Quantum 589 T83Thunderbolt Ok101 Quantum 7406 T834 Tomahawk Ok102 Quantum 7460 T111Tonkawa Okfield Ram T113G Trailblazer Onaga Rawhide T118 Trego OroBlanco Redland T129 Triumph/Triumph 64 Overland Rio Blanco T136 TutOverley Ripper T140 Venango Payne Rocky T193 Victory Pecos RonL T213Vista Plainsman V Rowdy T91 Vona Platte Sage TAM W 101 Voyager PonderosaSalute TAM 105 Wahoo Pony Sandy TAM 107 Weathermaster 135 Postrock SantaFe TAM 108 Wesley Prairie Red Scout TAM 109 Windstar Prairie WhiteSierra TAM 110 Wings ProBrand 830 Siouxland/Siouxland 89 TAM 111Winterhawk Protection Shocker TAM 112 Wrangler Prowers/Prowers 99 SmokyHill TAM 200 Yuma Prowers 99 Stallion TAM 202 Yumar Quantum 561 StantonTAM 203 Quantum 562 Sturdy TAM 301See, http://www.thewheatfarmer.com/varieties_list.shtm.

The polymers of the invention may also include plant growth regulators.These may be present in a variety of amounts depending upon the type ofregulator and the intended use. The regulators are typically added afterthe polymers are synthesized and supplemented with micronutrients.Depending upon the charge of the plant growth regulators, they may bebonded or complexed with the polymer or present in the polymer/aqueousmedium. For example, cationic or amphoteric plant growth regulators tendto bond or complex with the polymer, whereas anionic species do not.

Typical plant growth regulators which can be used with the polymers ofthe invention include one or more of the following regulators:

Antiauxins: clofibric acid, 2,3,5-tri-iodobenzoic acid;

Auxins: 4-CPA, 2,4-D, 2,4-DB, 2,4-DEP, dichlorprop, fenoprop, IAA, IBA,naphthaleneacetamide, a-naphthaleneacetic acids, 1-naphthol,naphthoxyacetic acids, potassium naphthenate, sodium naphthenate,2,4,5-T;

Cytokinins: 2iP, benzyladenine, 4-hydroxyphenethyl alcohol, kinetin,zeatin;

Defoliants: calcium cyanamide, dimethipin, endothal, ethephon, merphos,metoxuron, pentachlorophenol, thidiazuron, tribufos;

Ethylene Inhibitors: aviglycine, 1-methylcyclopropene;

Ethylene Releasers: ACC, etacelasil, ethephon, glyoxime;

Gametocides: fenridazon, maleic hydrazide;

Gibberellins: gibberellins, gibberellic acid;

Growth Inhibitors: abscisic acid, ancymidol, butralin, carbaryl,chlorphonium, chlorpropham, dikegulac, flumetralin, fluoridamid,fosamine, glyphosine, isopyrimol, jasmonic acid, maleic hydrazide,mepiquat, piproctanyl, prohydrojasmon, propham, tiaojiean,2,3,5-tri-iodobenzoic acid

-   -   Morphactins: chlorfluren, chlorflurenol, dichlorflurenol,        flurenol);

Growth Retardants: chlormequat, daminozide, flurprimidol, mefluidide,paclobutrazol, tetcyclacis, uniconazole;

Growth Stimulators: brassinolide, brassinolide-ethyl, DCPTA,forchlorfenuron, gamma-aminobutyric acid, hymexazol, prosulcr,pyripropanol, triacontanol;

Signalling Agents: Ca²⁺, inositol phospholipids, G-proteins, cyclicnucleotides, protein kinases, protein phosphatases, sodium glutamate;

Unclassified Plant Growth Regulators: bachmedesh, benzofluor, buminafos,carvone, choline chloride, ciobutidc, clofencet, cloxyfonac, cyanamide,cyclanilidc, cycloheximide, cyprosulfamide, epocholeone, ethychlozate,ethylene, fuphenthiourea, furalane, heptopargil, holosulf, inabenfide,karetazan, lead arsenate, methasulfocarb, prohexadione, pydanon,sintofen, triapenthenol, trinexapac.

The complete micronutrient-supplemented polymers of the invention, withor without the inclusion of plant growth regulators, may be applied toseeds by any convenient means, such as spraying or dipping. In terms ofamounts, the polymers should be used at a level of from about 0.1-25 oz,more preferably from about 2-7 oz and most preferably about 6 oz, per100 lbs of seed. These ranges refer to the preferred aqueous polymermixtures containing about 40% by weight polymer. Therefore, these rangestranslate to from about 0.04-10 ounces micronutrient polymer per 100 lbsof wheat seed, more preferably from about 0.8-2.8 ounces and mostpreferably about 2.4 ounces.

EXAMPLES

The tested polymer product was the presently most preferred product madeup of a 40% solids aqueous polymer partial salt mixture wherein thepolymer fraction contained substantially equimolar amounts of maleic anditaconic repeat units. The polymer mixture included about 2% by weightZn, about 1% by weight Mn, and about 200 ppm of Cu, on a metals basis.In addition, the aqueous polymer mixture as prepared included sufficientsodium hydroxide to give the overall mixture a pH of about 6. Thedensity of the polymer mixture was about 11.1 lbs/gallon.

This micronutrient-supplemented aqueous polymer mixture was applied byspraying onto wheat seed, followed by allowing the mixture to dry sothat the dried residue of the mixture was applied to the wheat seedsurfaces. The treated wheat products were then tested to determine theyield advantage provided by the test polymer. In each case, the testwheat seeds were treated at a rate of either four or six ounces of theaqueous polymer mixture per 100 lbs of seed, and untreated control seedswere planted along with the coated seeds. Yields were calculated asbushels per acre.

TABLE A Crop Rate Yield Yield Advantage Location Wheat Control 77.8 cManhattan, KS Wheat 4 oz 83.6 5.8 Wheat 6 oz 83.6 6.7 Wheat 4 oz 81.05.8 Wheat 6 oz 84.5 3.2

TABLE B Crop Rate Yield Yield Location Wheat Control 83.5 c Clemson, SCWheat 4 oz 83.8 0.3 Wheat 6 oz 85.1 1.6 Wheat 8 oz 86.5 3.0

A series of controlled, directly comparative tests were undertaken withvarious varieties of corn, wherein the most preferred product describedabove was employed.

In one such test, four corn hybrids (Croplan 2123VT2P/RIB, DKC 30-23,INT 9333VT2PRO/RIB, and Pioneer P8210HR) were tested under identicalfield and growth conditions. For each hybrid, there were four controltrials without seed coating and four coated trials seed trials where thepolymer product was applied to the seed at a level of 6 oz per 100 lbsof seed. At the conclusion of the test, the results were averaged,giving the following data:

TABLE C Hybrid Treatment Average Yield (Bu/acre) CL 2123 Control 108.1CL 2123 Polymer Coated 135.97 INT 9333 Control 130.45 INT 9333 PolymerCoated 141.85 P8210 Control 107.2 P8210 Polymer Coated 120.99 30-23Control 111.28 30-23 Polymer Coated 115.15

In another directly comparative test, the amount of polymer product wasvaried to determine the yield effect. In particular, the corn hybrid wasDKC-64-69, and yield tests were performed using a non-coated control,and the most preferred polymer product at levels of 4 and 6 oz per 100lbs of seed. In this study, the control gave a yield of 155.1 Bu/acre,the 4 oz trial gave a yield of 156.8 Bu/acre, and the 6 oz trial gave ayield of 164.8 Bu/acre.

It has also been found that the compositions of the invention areeffective for reducing nematode infestations, such as soybean cystnematodes (Heterodera glycine), which are parasitic to soybean plants(Glycine Max). These nematodes damage soybean root structure anddecrease yields in the US by nearly 1 billion dollars per year. Thesenematode infestations are difficult to identify and control, even withthe use of nematocides and crop rotations.

Five field trials were undertaken at diverse locations throughout theMidwest to cover a variety of geographies and soil types. Within eachtrial, four replications were completed, and each replication wassampled for nematode cysts consisting of 6-8 consolidated soil cores.The samples were analyzed for cyst nematode eggs per 100 cc of solution,using a standard assay. In the test, untreated seeds were planted alongwith seeds coated with the preferred composition of the invention,applied at a rate of 6.0 fluid ounces of the composition per 100 poundsof seed. A dry formulation containing the polymer was applied to a thirdquantity of seeds at a rate of 3.76 ounces of the dry material per 100pounds of seed.

The seed treatment unexpectedly reduced soybean cyst nematode (SCN) eggcounts significantly, compared to the untreated control. The followingsummarizes the test data:

TABLE D Average of 5 Test Sites, 4 Replications/Site SCN eggs per 100 ccUntreated Control Seeds 975 Treated Seeds - Aqueous Composition 525Treated Seeds - Dry Composition 663

Further disclosure pertaining to the Class I polymers and uses thereofis set forth in U.S. patent application Ser. 62/001,110, filed May 21,2014, which is fully incorporated by reference herein.

I claim:
 1. A water soluble coating composition for seeds, comprising apolymer have a backbone containing maleic, itaconic, and two sulfonaterepeats units and having micronutrients selected from the groupconsisting of Fe, Mg, alkaline earth metals, and mixtures thereof,wherein said polymer is in a partial salt form, wherein said polymer hasat least 80 mole percent of repeat units including at least one anionicgroup, where the total amount of all of the repeat units in the polymeris taken as 100 mole percent, and wherein said coating composition has apolymer content of from about 35% to about 55% by weight based on thetotal weight of the coating composition.
 2. The coating composition ofclaim 1, said micronutrients being chemically bound to said polymerbackbone.
 3. The coating composition of claim 1, wherein the alkalineearth metal is Ca.
 4. The coating composition of claim 1, said coatingcomposition being an aqueous mixture containing said polymer.
 5. Thecoating composition of claim 4, said mixture having a pH of about 3-8.6. The coating composition of claim 5, said mixture having a pH of about4-6.5.
 7. The composition of claim 1, wherein said two sulfonate repeatunits are allylsulfonic repeat units and methallylsulfonic repeat units.8. The composition of claim 1, said polymer having about 1-20 molepercent methallylsulfonic repeat units and about 0.1-10 mole percentallylsulfonic repeat units, where the total amount of all of the repeatunits in the polymer is taken as 100 mole percent.
 9. The composition ofclaim 1, wherein the partial salt form further comprises boron.
 10. Amethod of treating seeds comprising the step of coating seeds with thecoating composition of claim
 1. 11. The method of claim 10, said seedsselected from the group consisting of wheat and corn.
 12. The method ofclaim 10, said coating composition being applied by spraying onto saidseeds, or by dipping the seeds in the coating composition.
 13. A seedproduct comprising a seed having on the surface thereof the coatingcomposition of claim
 1. 14. The seed product of claim 13, wherein saidseed is selected from the group consisting of wheat and corn.
 15. Thecoating composition of claim 1, wherein the polymer comprises about 2-40mole percent of sulfonated repeat units, where the total amount of allof the repeat units in the polymer is taken as 100 mole percent.
 16. Thecoating composition of claim 1, wherein the anionic polymer comprisesmaleic acid 35-50 mole percent, itaconic 20-55 mole percent,methallylsulfonic acid 1-15 mole percent, and allyl sulfonic acid 1-20mole percent, where the total amount of all of the repeat units in thepolymer is taken as 100 mole percent.
 17. The method of claim 10,wherein the polymer comprises about 2-40 mole percent sulfonated repeatunits, where the total amount of all of the repeat units in the polymeris taken as 100 mole percent.
 18. The method of claim 10, wherein theanionic polymer comprises maleic acid 35-50 mole percent, itaconic 20-55mole percent, methallylsulfonic acid 1-15 mole percent, and allylsulfonic acid 1-20 mole percent, where the total amount of all of therepeat units in the polymer is taken as 100 mole percent.